While the present invention, as will be apparent hereinafter, is applicable to hanging a wide range of articles, the following discussion will be in the context of hanging pictures although it is not intended that the invention be limited thereto. Wall hanging of pictures, such as in the home, is accomplished most often by use of a metal hook having a vertical shank, and a roughly triangular nail holder at the top of the shank which permits a nail to be driven into the wall in an angular or toed orientation. Where a particular pattern of framed pictures, such as in a straight horizontal array, is desired, precise measurements must be made to achieve a linear alignment of the hangers. Some compensation for a failure to achieve precise alignment or position can be had by increasing or decreasing the slack in the usual hanging wire which extends across the rear of the frame. However, it often happens that misalignment is substantial, and cannot thus be remedied. In such case, the hanger itself must be repositioned, necessitating creating a new nail hole, and leaving an unsightly empty hole in the wall.
There are numerous prior art arrangements for achieving a greater degree of adjustment of hanger position. In U.S. Pat. No. 2,478,256 of Eysmann, for example, a flat plate has a plurality of vertically spaced hooks on the rear (wall side) face thereof, and a centrally positioned vertically extending slot through which a picture hook can be supported by the rear facing hooks. The height adjustments of the picture hook are limited to spaced increments, and a recess in the wall is required.
In U.S. Pat. No. 3,360,229 of Beyer, the picture hanger comprises a plurality of vertically spaced hooks, thereby allowing only discrete incremental positioning of the picture.
U.S. Pat. No. 2,697,572 of Pfankuch, et al. discloses an adjustable hanger in which a hook portion slidably mounted to a wall mounted member, and is raised or lowered by means of a vertically extending threaded bolt which extends between the two elements. Such an arrangement permits minute changes in the height of the hook, eliminating the incremental steps of the Beyer and Eysmann arrangements but the amount of change is limited by the length of the bolt. Other incremental step adjustments are shown in U.S. Pat. No. 6,152,418 of Panicci, U.S. Pat. No. 6,666,425 of Ferguson, and Des. U.S. Pat. No. 349,447 of Daniller, all of which are directed to adjusting the height of a picture, for example. In the prior art, as exemplified by the foregoing patents, vertical adjustment is generally achieved in incremental steps, with attendant limitation on achieving the exact picture height desired.